Hunting and Sneaking through the rooftops, bending magic to their will to fight, This is the way of the Ronin

Shadow Blade

Starting when you choose this tradition at 3rd level, you can manipulate your blades Ki when you harness your own. You may coat your blade in shadows for 1 Ki point as a bonus action,  this lasts for 1 minute, when the blade is coated in shadow it gains these properties

It deals necrotic damage 

when you hit the enemy with it they must succeed on a wisdom saving throw or be blinded until the end of their next turn

Ronin Training

When you choose this Tradition at level 3

You gain proficency with Longswords and you gain proficency with the stealth skill

Longswords count as monk weapons for you and they count as finnese for you

Shadow Magic

Starting at level 6 you learn to weave darkness to be lethal

You may cast darkness for 2 Ki points, when in this darkness you have magical darkvision

Your Dark Blade gains a damage bonus equal to your Wisdom Modifier

The dark blade is magical for the purpose of overcoming resistances

Rooftop Runner

At level 11, You gain a climb speed equal to your movement speed, you gain advantage on all acrobatics checks

Advanced DarkBlade

At level 17 you unlock your darkblade's true potential

You unlock your Darkblade's true potential and gain these benfits

When an enemy fail the saving throw for Blind Strike you can attack them again you may use this once per short rest (Free Acion)

On a critical hit you regain half the damage you dealt with the Darkblade